<!doctype html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="maximum-scale=1.0,minimum-scale=1.0,user-scalable=0,width=device-width,initial-scale=1.0"/>
    <meta name="format-detection" content="telephone=no,email=no,date=no,address=no">
    <title>用户登录</title>
<style>
body{
  font-size:100%;
}

h1{
  font-size:1em;
}
</style>
</head>
<body>
<p>
  123
</p>
<h1>
  123
</h1>
</body>
</html>
